/**
 * Snippet from http://snippets.dzone.com .
 *
 * Licensed under the WTFPL (http://sam.zoy.org/wtfpl/).
 */
package de.sendorian.util.io;


import java.io.File;
import java.io.FileFilter;
import java.util.Arrays;
import java.util.Iterator;

import de.sendorian.util.FlatteningIterator;

/**
 * Iterates over all non-directory files contained in some subdirectory of the current one.
 *
 * @author david
 */
public class RecursiveFileListIterator implements Iterator<File> {
	private final FlatteningIterator flatteningIterator;


	public void remove() {
	}


	public RecursiveFileListIterator(File file, FileFilter filter) {
		flatteningIterator = new FlatteningIterator(new FileIterator(file, filter));
	}


	public RecursiveFileListIterator(File file) {
		this(file, null);
	}


	public boolean hasNext() {
		return flatteningIterator.hasNext();
	}


	public File next() {
		return (File) flatteningIterator.next();
	}

	/**
	 * Iterator to iterate over all the files contained in a directory. It returns a File object for
	 * non directories or a new FileIterator obejct for directories.
	 */
	private static class FileIterator implements Iterator<Object> {
		private final Iterator<File> files;

		private final FileFilter filter;


		FileIterator(File file, FileFilter filter) {
			files = Arrays.asList(file.listFiles(filter)).iterator();
			this.filter = filter;
		}


		public void remove() {
		}


		public Object next() {
			File next = files.next();

			if (next.isDirectory()) {
				return new FileIterator(next, filter);
			} else {
				return next;
			}
		}


		public boolean hasNext() {
			return files.hasNext();
		}
	}
}

